BETTER THAN GINKGOScientist Ted
Berger created a computer chip that mimics the neural
circuitry of the hippocampus, a brain region essential for
memory. Here's how it works on rat brain tissue.

Electrodes intercept electrical signals bound for
damaged tissue in the hippocampus. The signals reroute to the
chip, which acts like a cluster of neural circuits to process
data and send it back to the brain.

Illustration by Garry Marshall

Damage to the hippocampus often
destroys a person's ability to store new memories. A
computer chip that can fill in for faulty brain circuits
could be less than 15 years away.

In a few months, researchers at the
University of Southern California will test the world's first
prosthetic brain part. Biomedical engineer Theodore Berger has
created a 2 mm-wide silicon chip that he hopes will one day
substitute for damaged or diseased brain regions, holding
promise for victims of Alzheimer's disease, stroke and other
brain traumas.

Berger engineered the chip using
mathematical models based on rat brain circuits. He'll test it
on slivers of brain tissue spliced from a rat's
hippocampus—gray matter responsible for retaining new,
long-term memories. In the experiment, millions of neurons
embedded in the tissue will transmit their electrical impulses
to attached electrodes. If all goes according to plan, the
electrodes should intercept the signals and reroute them to
the chip, which fills in for the damaged neural circuits to
process the data and shoot it back to other neurons. "It's an
elegant experiment," says computer neuroscientist Richard
Granger at the University of California at Irvine. "And a
tantalizing glimpse of things to come."

Medicine
aside, Berger sees potential commercial and military
applications for the brain chip, which is partially funded by
the Defense Advanced Research Projects Agency. Learning how to
build sophisticated electronics and integrate them into human
brains could one day lead to cyborg soldiers and robotic
servants, he says.

Other scientists doubt such heady
claims. The brain remains the most sophisticated circuit board
ever created, and researchers may never figure out how to
accurately connect chips and electrodes with its billions of
neurons. "It's very doubtful that Berger's model can do the
same thing the hippocampus does," says Steve Potter, who has
undertaken similar research at Georgia Tech
University.